• Ethernet Local Management Interface (ELMI): ELMI is a protocol between the service provider network and the customer equipment. It lets the customer equipment communicate its status and different service characteristics to the service provider network to ease troubleshooting and deployments.

• Network Node Interface (NNI) on all ports on MetroIPAccess image: Currently, Cisco ME3400 Series Ethernet Access Switches have a limit of four NNIs. This provides a configurable option to allow the restriction to be removed on the MetroIPAccess image.

• Non-stop forwarding (NSF) awareness: This feature enhances the Border Gateway Protocol (BGP), IS-IS, OSPF, and Enhanced Interior Gateway Routing Protocol (EIGRP) routing protocols so that they are "aware" of being connected to a router supporting Cisco NSF. It speeds convergence when the NSF router goes through a failover sequence.

• Secure Copy Protocol (SCP): SCP allows a user with appropriate authorization to copy any file that exists in the Cisco IOS Software file system to and from a switch by using the copy command. This protocol uses the Secure Shell (SSH) Protocol as a transport mechanism for file copy operations, so that software images, configuration files, and so on can be transferred to or from the switch over a secure channel. It also uses authentication, authorization, and accounting (AAA) to authorize a user's privilege level.

• FlexLinks bidirectional fast convergence: Improves the downstream convergence time for FlexLinks ports by triggering the upstream switch to flush its MAC address. The message is sent after FlexLinks failover. With the MAC address table flushed, the next packet downstream will be flooded out all ports rebuilding the MAC address table.

• FlexLinks reemption: Currently within FlexLinks, the switch port backup interface feature allows users to configure a Layer 2 interface to back up another Layer 2 interface. The two interfaces provide mutual backup to each other: that is, only one of the interfaces forwards traffic and is called the "active interface." The other one is in backup mode, which is not forwarding traffic and is ready to take over in case the forwarding interface is down and is called the "backup interface." When the active interface goes down, the backup interface takes over as active and starts forwarding traffic.

With this enhancement the customer can control the behavior of the "original" active interface when it comes back up:

– If preemption mode is off, this interface will go into backup mode.

– Configure preemption mode to always force a switchover to the "original" active.

– Configure preemption mode to switch over to higher available bandwidth interface.

• CISCO-PORT-QOS-MIB: Provides information about QoS statistics, which are currently available using the command-line interface (CLI) using Simple Network Management Protocol (SNMP).

• Link state tracking: Link state tracking, also known as trunk failover, provides Layer 2 redundancy in the network when used in conjunction with server network interface card (NIC) adapter teaming.

• DHCP option 82 configurable remote ID and circuit ID: DHCP option 82 provides customers a great deal of flexibility when it comes to identifying individual users for various reasons-for example, location of attachmen, or controlling how many IP addresses a device or user is allowed from the DHCP server. This enhancement provides customers additional flexibility to determine what information is provided within the option 82 remote ID suboption and option 82 circuit ID suboption.

– Remote ID: The customer now has the option to use a switch's configured hostname or specify an ASCII text string. Both are subject to a maximum length of 63 bytes. The default is to provide the MAC address of the switch.

– Circuit ID: The customer now has the option to configure an ASCII text string up to 63 bytes and override the default circuit ID, which is vlan-module-port in binary format.

• CNS Image Agent: Enhances the existing CNS functionality implemented on the Cisco CNS 2100 Series Intelligence Engine with support of the new CNS Image Agent capability. CNS Image Agent works with the CNS Image Server and allows for the distribution of images to the switch.

Because of export restrictions on strong cryptography software, a separate image is required for the cryptographic features (SSH, SNMPv3, and Kerberos Protocol). These software images can be downloaded from the corresponding Triple Data Encryption Standard (3DES) area of the links provided in this section. Note that the Cisco Advanced IP Services license is available only in cryptographic format.